A prober is known as a substrate inspection apparatus that inspects electrical properties of semiconductor devices, e.g., power devices or memories, formed on a semiconductor wafer (hereinafter, simply referred to as a “wafer”) as a substrate.
The prober includes a probe card having a plurality of needle-shaped probes, and a stage having a wafer loaded thereon and freely moving in upward, downward, left and right directions. Each probe of the probe card is brought into contact with an electrode pad or solder bump included in the semiconductor device. Then, an inspection current is applied to the electrode pad or solder bump from each probe, thereby inspecting the electrical properties of the semiconductor device.
The prober in the related art is connected to an IC tester that inspects electrical properties or functional faults of the semiconductor device. The circuit configuration of the IC tester is different from the circuit configuration in which a commercialized semiconductor device is mounted, e.g., the circuit configuration of a motherboard or functional expansion card. Thus, the IC tester cannot perform the inspection of the semiconductor device in its mounted state. As a result, there is a problem in that a problem of the semiconductor device, which is not detected by the IC tester, is found when the semiconductor device is mounted on the functional expansion card, or the like. In particular, recently, the processing performed by the motherboard or functional expansion card is complicated and performed at a high speed, and the circuit configuration of the motherboard or functional expansion card is complicated. Thus, the difference between the circuit configuration of the motherboard or functional expansion card and the circuit configuration of the IC tester is increased, and the problem described above became significant.
Therefore, in order to guarantee the quality of a semiconductor device, instead of the inspection performed by the IC tester, there is proposed a technique in which there is installed an inspection circuit that reproduces the circuit configuration where the semiconductor device is mounted on a probe card, e.g., the circuit configuration of a functional expansion card. In the technique, the electrical properties of the semiconductor device are measured without cutting the semiconductor device from a wafer in a state where the state of the semiconductor device mounted on the functional expansion card is imitated using the probe card. The inspection in the state where such a mounted state is imitated is referred to as a wafer system level test.
However, in order to accurately measure the electrical properties of the semiconductor device, it is necessary to perform a test (contact check) for determining whether a probe of the probe card and an electrode pad or the like of the semiconductor device are electrically in contact each other before the measurement. In the related art, a prober is connected to an IC tester, and the contact check is performed by applying a voltage to the electrode pad of the semiconductor device using an IFVM (I Force V Measure) function of a DC module provided in the IC tester. In addition, when an abnormal state is detected in the contact check, a cause of the abnormal state is determined based on a value of the voltage.
However, in a prober that performs the wafer system level test instead of the test performed by the IC tester, a high-priced IC tester is not used. Hence, the contact check cannot be performed by a DC module, and of course, a cause of an abnormal state regarding the contact between the probe and the electrode pad or the like cannot also be determined.